Mixing apparatus



Aug. 10, 1965 R. w. MOORE ETAL 3,199,844

MIXING APPARATUS Filed oct. 19, 1961 INV ENTORS Ralph WMoore Oil/6MM Socym United States Patent C 3,19%,844 MEHNG APPARATUS Ralph W. Moore and Owen M. Stoops, Hagerstown, Md., assignors to Panghorn Corporation, Hagerstown, Md., a corporation of Maryland Filed Oct. 19, 1961, Ser. No. 146,144 4 Claims. (Cl. 259-4) This invention relates to a -particle mixing device, more specifically to a device for supplying particles of abrasive or the like to a iiuid stream.

Devices of the above character have been in use but are subject to diiiiculties. There is a tendency for the particles of abrasive or the like to work their way into the moving parts of the device and to quickly wear them out either by direct scouring or through movement of the parts themselves over the abrasive.

An additional diflculty is encountered when it becomes necessary to check and maintain the valves and other control parts. The particles are then apt to be spilled all over the tloor, particularly where the abrasive material is being fed from a pressurized source.

It is an object of the present invention to provide an improved mixing device that alleviates the above diiculties.

.A further object is to provide a mixing device that can be used with a pressurized abrasive supply tank and that can be maintained in a relatively simple manner.

Other objects and advantages will become apparent in the ensuing specification and appended drawings of which:

FIG. 1 is a vertical cross section of one form of mixing device of the present invention;

FIG. 2 is a similar view of the mixing device of FIG. 1, with supplemental modifications:

FlG. 3 is a cross section of an embodiment of the construction of FIG. 2; and

PIG. 4 is a similar cross-sectional View of a mixing device embodying the present invention with the mixing device partly separated.

Referring now to the drawings in detail, the apparatus shown in FIG. 1 comprises a mixing chamber 1 having a roof 2, side walls 3 and a floor 4, said mixing chamber being also provided with a propellant fluid intake port 5, propellant exhaust port 6, an abrasive feed port 7 equipped with hardened valve seat 8, a flexible diaphragm seal 9 across the oor of said mixing chamber, a vertically reciprocal valve plunger 10 having a beveled head 18, a valve actuating means 11 including an actuating cylinder 12 with reciprocal piston 13, ian attached piston rod 14 connected to the exible diaphragm seal 9 and reciprocal valve plunger lll, an upper 'cylinder port 1S and a lower cylinder port 16 for cylinder 12, and a spring 17 exerting an upward force against piston 13. The spring is backed up by a base 2li which can also carry a fixed or adjustable limit stop such as threaded rod 22, for the piston.

In use, chamber 1 of the construction of FIG. 1 is secured as by bolting, to the bottom of a tank that contains a supply of the particles to be propelled. A gasket 24 can be used to seal the joint between the tank and the chamber. A source of pressurized control air can be connected to cylinder port 15, and a source of pressurized propellant air to port 5. The propellant exhaust port 6 can then be connected to a conduit that has a nozzle for directing the propelled stream of particlecarrying air against work surfaces to be abraded, peened, cleaned or the like. With the control air supply shut off, spring 17 holds the head of valve 10 against the mating surface of valve seat 8, thus keeping particles from entering the chamber. When the control air pressure is applied to upper cylinder port 15, the piston 13 is pushed downwardly, compressing spring 17 and carrying piston rod 14 down with it. The reciprocal valve plunger 1i) is thereby lowered, causing beveled head 18 to become unseated and opening abrasive feed port 7. A stream of abrasive material thereupon enters mixing chamber 1 between propellant fluid intake port 5 and propellant exhaust port 6, and is expelled through exhaust port 6. Flexible diaphragm seal 9 keeps these particles from Working their Way into the actuating mechanism.

At anytime during such operation the control air pressure can be released, as yby a control located near the discharge nozzle, and the valve will then close under the influence of spring 17. If desired, the valve closing can be effected by lanother pressurized air connection to lower cylinder port 16.

A preferred actuating fluid for the above-described mixing device is a gas such as compressed air which is inexpensive and may be easily fed int-o and bled out of the cylinder ports, although other inert gases and also various liquids like water, may be substituted for the purpose of the .present invention.

The threaded rod 22 can be set to determine the maximum opening of the valve, and can also be reset during use to alter this opening. Where an adjustable stop is used the adjusting connection can be sea-led against leakage to keep the particles being propelled from finding their way into the mechanism through this route. Also such a seal is needed if lower cylinder port 16 is to be used for receiving control pressure. A gasket Si) sequeezed against the bottom of base 2t? by a locknut 28 makes a very effective seal for these purposes.

The diaphragm seal 9 may be securely -held in sealed relation to the movable valve plunger 10 and/or piston rod 14 as by having the plunger and rod threadably engaged to each other through an opening in the diaphragm, with these threadably engaged parts clamped around the entire periphery on both faces of the diaphragm opening. The diaphragm should be constructed of resilient tough material such as leather, vulcanized rubber sheeting, plastics such as Teflon, or resin-impregnated fabrics that have the desired characteristics of good ilexibility, high tear rstrength and sufficient fatigue resistance to withstand the pressure and flexure required in the operation ofthe mixing device.

FiG. 2 shows a pressurized abrasive tank 21 combined with the mixing device of FIG. l and with an O-ring type of gasket 52 used in .place of the tlat gasket 24. The tank has a iloor plate 34 with an out-let port 36 against which the mixing device is held so that the abrasive feed port 7 is located directly under this opening. An automatic shutoif device which comprises a housing 25 containing -passageways 49 for particles to flow through is mounted immediately above tank oor plate 34. Within the housing 2S is a ball check 42 and a spring 44 compressed between the ball check and the inside of the housing top 26. The ball check is large enough to completely cover tank outlet port 36 but it carries a spacer foot e6 that is narrow enough to lit through this opening. The spacer foot rests on the roof 2 of the mixing charnber around abrasive feed port 7. The mixing chamber is attached to ythe abrasive tank by hinge 60 and a locking device comprising a slidable safety latch bar 32 and quick opening toggle clamp 33 comprising lock support 51, lock lever 48 equipped with locking tip 47 and pivotally connected to lock support 51, toggle clamp handle 54 pivotally mounted on lock lever 43 and guide links 56 endwise ,pivotally mounted on lock support 51 and `toggle clamp handle 54.

FIGURE 4 shows the mixing apparatus when opened for inspection purposes, safety latch bar 32 having been withdrawn and toggle clamp 33 opened by pulling toggle handle 54, allowing mixing chamber 1 to swing free on hinge 60 and ball check 42 caused to close on abrasive tank outlet port 36, by the downwardly directed force of spring 44.

FIGURE 3 shows a similar combination of the automatic shut-off device shown in FIGURES 2 and 4 with a simple mixing device comprising an overhead abrasive feed port 7A, a mixing chamber 1A, a propellant intake port (not shown) and a propellant exhaust port 6A.

When the mixing apparatus of the type described in FIGURES 2 and 4 is in operation, a stream of abrasive particles is forced under pressure from tank 21 through tank outlet por-t 36 and abrasive feed port 7, falling downwardly into a stream `of rapidly moving propellant ilow-V ing between intake port and exhaust port 6. If it 'becomes necessary to inspect, clean, or replace any part of the mixing chamber the chamber is made accessible by pulling clamp handle 54 and withdrawing safety latch bar 32. The chamber thereupon swings free on hinge 60, and ball check 42 actuated by spring 44 descends to shut off the abrasive tank out-flow and prevent loss of abrasive material as well as pressure.

The quick acting toggle clamp 33 in the construction of FIGS. 2, 3 and 4, is very desirable because it effectively holds the chamber sealed in place under the supply tank, and yet is so simple to operate. A single movement is suicient to lock or open the clamp. The operation is so simple that the safety latch bar is very helpful in avoiding inadvertent unlocking of the chamber. It will lbe noted that the locking tip 47 is made so short that it `will not engage or lock in place unless the latch bar is in a latching position. This assures the latching of the chamber in its operative position whenever it is locked, and thereby also assures the latching of the chamber in place should an operator accidentally ltrip the toggle clamp open.

Although the tanks of FIGS. 2, 3 and 4 have been described as abrasive tanks, they can be used to supply particles of widely different characteristics, from highly abrasive ones such as sand or metal shot, to the very weakly abrasive ones such as granular corn cobs or the like. All such particles can also be used in the construction of FIG. 1.

In the above described mixing devices, it is preferred to employ a hardened metal such as a high chromium molybenum ferrous alloy or similar abrasive-resistant metal in the valve seats, valve and propellant exhaust port.

A number of propellant materials known to the art may be employed with the present device. Included among these are compressed air, nitrogen and water; the propellant customarily operates under an approximate pressure range from about lO-lOO p.s.i. although pressures outside of this range may be employed if necessary.

Since it is obvious that many changes and modifications can be made in the above-described details without departing from the nature and spirit of the invention, it is to be understood that the invention is not to be limited to said details except as set forth in the appended claims.

lWhat is claimed:

1. A mixing chamber having a supply por-t for receiving particles to be propelled, and a propellant passageway communicating with and under said port and extending across the chamber, a valve member in said chamber positioned to move into and out of sealing engagement with said supply port to selectively close and open the supply of said particles, valve actuating means below said passageway and connected to the valve member through an opening in the bottom of the passageway, a flexible diaphragm seal secured to the valve member for sealing ofi said opening, and said supply port being in a chamber wall hingedly connected to pivot toward and away from a wall of a particle supply tank and this tank wall has a discharge port communicating with the port when the chamber is lpivoted toward the tank wall.

2. A mixing apparatus including a particle supply tank having a floor with an outlet for delivering the particles from the tank, a propellant uid conduit below said outlet and having a passageway communicating with it, said conduit -being hinged to the tank to pivot the passageway toward and away from the outlet, locking means on the conduit and the tank for locking the conduit against the outlet to form a port for delivery of the particles to the uid propellant in said conduit, said locking means consisting of a clamp having limited locking travel and a movable latch bar shiftable into and out of latching position in engagement with the conduit, the clamp being positioned so that its limited locking travel is suflicient to lock against the latch 4bar when in latching position, but insufiicient to lock when the latch bar is in any other position, and replaceable metering means in said port.

3. A device according to claim 2 in which a biased resilient closure member is positioned opposite the port, said closure member having an extension that is engaged by the apparatus when the conduit is pivoted into particle delivering position, to hold the closure member away from the port, and to cause the closure member to automatically close the port when the conduit is pivoted away from particle delivering position.

4. A mixing apparatus including a lparticle supply tank having a oor with an outlet for delivering particles from the tank, a propellant uid conduit below said outlet and having a passageway communicating with it, said conduit being hinged to the tank to pivot the passageway toward and away from the outlet, locking means on the conduit and the tank for locking the conduit against the outlet to form a port for delivery of the particles to the fluid propellant in said conduit, a resilient closure member positioned above the iloor outlet, means for urging said resilient member against the floor outlet, and an extension connected with said closure which is urged upwardly to 1n turn urge the resilient closure out of the floor outlet when the conduit is pivoted against the iloor of the tank.

References Cited by the Examiner UNITED STATES PATENTS 1,566,814 12/25 Bliss 251-63 X 1,585,549 5/26 Jorgensen 51-12 2,146,917 2/39 Rosenberger 51-12 X 2,297,548 9/42 Fox et al. 251-1496 X 2,728,547 12/55 Crookston et al 251-63 X y2,924,233 2/ 60 Michaels 251-335 X 3,061,196 10/62 Bauerlein 251-335 X l/VALTER A. SCHEEL, Primary Examiner.

LEO QUACKENBUSH, Examiner. 

4. A MIXING APPARATUS INCLUDING A PARTICLE SUPPLY TANK HAVING A FLOOR WITH AN OUTLET FOR DELIVERING PARTICLES FROM THE TANK, A PROPELLANT FLUID CONDUIT BELOW SAID OUTLET AND HAVING A PAWSSAGEWAY COMMUNICATING WITH IT, SAID CONDUIT BEING HINGED TO THE TANK TO PIVOT THE PASSAGEWAY TOWARD AND AWAY FROM THE OUTLET, LOCKING MEANS ON THE CONDUIT AND THE TANK FOR LOCKING THE CONDUIT AGAINST THE OUTLET TO FORM A PORT FOR DELIVERY OF THE PARTICLES TO THE FLUID PROPELLANT IN SAID CONDUIT, A RESILIENT CLOSURE MEMBER POSITIONED ABOVE THE FLOOR OUTLET, MEANS FOR URGING SAID RESILIENT MEMBER AGAINST THE FLOOR OUTLET, AND AN EXTENSION CONNECTED WITH SAID CLOSURE WHICH IS URGED UPWARDLY TO IN TURN URGE THE RESILIENT CLOSURE OUT OF THE FLOOR OUTLET WHEN THE CONDUIT IS PIVOTED AGAINST THE FLOOR OF THE TANK. 